Description: 高分辨率要求系统具有大的带宽，瞬时带宽的增加必将提高系统对硬件的要求，本文采用方便灵活的步进频率波形信号。脉间频率步进波形通过子脉冲载频的步进变化来获得大的有效带宽，使成像具有高分辨率，采用加窗和补零方法提高信噪比，但该信号对目标径向速度非常敏感。采用补零方法提高距离取样分辨率，使距离像细化，并用公式说明了补零只能提高距离取样分辨率，并不能改变频率步进信号的距离分辨能力。该信号波形对目标径向速度的敏感，使目标能量分散到邻近的距离单元造成距离分辨率下降，如果不事先进行速度补偿，直接对回波信号进行逆傅立叶变换，将使所成一维距离像发生频谱展宽，并伴有距离像发生平移。本文证明了当目标有径向速度时仍采用对回波信号直接进行逆傅立叶变换的方法将使一维距离像发生频谱展宽并伴有距离像发生频移，从而严重影响了一维距离像的质量。-high-resolution requirements of the system with large bandwidth, the increased instantaneous bandwidth will improve the system of hardware, In this paper, a flexible and convenient step frequency signals. Pulse frequency step-pulse waveform through the carrier frequency step to achieve great changes in the effective bandwidth. make imaging with high resolution, increasing the window and fill methods to improve signal-to-noise ratio is, However, the signal on the target radial velocity is very sensitive. Using zero-distance sampling method to improve resolution, so that distance as refinement, and formulates a zero-distance sampling can improve resolution, does not alter the frequency of the signal from stepping resolution capabilities. The signal waveform on the target radial velocity sens Platform: |
Size: 2351 |
Author:石榴石 |
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Description: 已知载波频率的扩频通讯MATLAB程序，通过扩展频率实现低信噪比的传输 -known carrier frequency of spread spectrum communication MATLAB program, through the expansion of low-frequency signal-to-noise ratio transmission Platform: |
Size: 1077 |
Author:zhouhui |
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Description: We address the problem of blind carrier frequency-offset (CFO) estimation in quadrature amplitude modulation,
phase-shift keying, and pulse amplitude modulation
communications systems.We study the performance of a standard
CFO estimate, which consists of first raising the received signal to
the Mth power, where M is an integer depending on the type and
size of the symbol constellation, and then applying the nonlinear
least squares (NLLS) estimation approach. At low signal-to noise
ratio (SNR), the NLLS method fails to provide an accurate CFO
estimate because of the presence of outliers. In this letter, we derive
an approximate closed-form expression for the outlier probability.
This enables us to predict the mean-square error (MSE) on CFO
estimation for all SNR values. For a given SNR, the new results
also give insight into the minimum number of samples required in
the CFO estimation procedure, in order to ensure that the MSE
on estimation is not significantly affected by the outliers. Platform: |
Size: 1265450 |
Author:吴大亨 |
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Description: 高分辨率要求系统具有大的带宽，瞬时带宽的增加必将提高系统对硬件的要求，本文采用方便灵活的步进频率波形信号。脉间频率步进波形通过子脉冲载频的步进变化来获得大的有效带宽，使成像具有高分辨率，采用加窗和补零方法提高信噪比，但该信号对目标径向速度非常敏感。采用补零方法提高距离取样分辨率，使距离像细化，并用公式说明了补零只能提高距离取样分辨率，并不能改变频率步进信号的距离分辨能力。该信号波形对目标径向速度的敏感，使目标能量分散到邻近的距离单元造成距离分辨率下降，如果不事先进行速度补偿，直接对回波信号进行逆傅立叶变换，将使所成一维距离像发生频谱展宽，并伴有距离像发生平移。本文证明了当目标有径向速度时仍采用对回波信号直接进行逆傅立叶变换的方法将使一维距离像发生频谱展宽并伴有距离像发生频移，从而严重影响了一维距离像的质量。-high-resolution requirements of the system with large bandwidth, the increased instantaneous bandwidth will improve the system of hardware, In this paper, a flexible and convenient step frequency signals. Pulse frequency step-pulse waveform through the carrier frequency step to achieve great changes in the effective bandwidth. make imaging with high resolution, increasing the window and fill methods to improve signal-to-noise ratio is, However, the signal on the target radial velocity is very sensitive. Using zero-distance sampling method to improve resolution, so that distance as refinement, and formulates a zero-distance sampling can improve resolution, does not alter the frequency of the signal from stepping resolution capabilities. The signal waveform on the target radial velocity sens Platform: |
Size: 2048 |
Author:石榴石 |
Hits:
Description: 已知载波频率的扩频通讯MATLAB程序，通过扩展频率实现低信噪比的传输 -known carrier frequency of spread spectrum communication MATLAB program, through the expansion of low-frequency signal-to-noise ratio transmission Platform: |
Size: 1024 |
Author:zhouhui |
Hits:
Description: We address the problem of blind carrier frequency-offset (CFO) estimation in quadrature amplitude modulation,
phase-shift keying, and pulse amplitude modulation
communications systems.We study the performance of a standard
CFO estimate, which consists of first raising the received signal to
the Mth power, where M is an integer depending on the type and
size of the symbol constellation, and then applying the nonlinear
least squares (NLLS) estimation approach. At low signal-to noise
ratio (SNR), the NLLS method fails to provide an accurate CFO
estimate because of the presence of outliers. In this letter, we derive
an approximate closed-form expression for the outlier probability.
This enables us to predict the mean-square error (MSE) on CFO
estimation for all SNR values. For a given SNR, the new results
also give insight into the minimum number of samples required in
the CFO estimation procedure, in order to ensure that the MSE
on estimation is not significantly affected by the outliers. Platform: |
Size: 1265664 |
Author:吴大亨 |
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Description: 采用频率调制 为1000Ｈｚ的载波，在解调前把加性白高斯噪声加入到调制信号。当噪声功率和调制信号功率比为０.００１，０.０１，０.０５，０.１和０.３是进行解调并绘出调制信号-The use of frequency modulation for the 1000Hz carrier, in the demodulation before AWGN added to the modulation signal. When the noise power and modulation signal power ratio of 0.3 is 0.001,0.01,0.05,0.1 and demodulation and modulation signals mapped Platform: |
Size: 1024 |
Author:金玲 |
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Description: 这是一本关于电子情报雷达信号分析的电子版，主要内容包括电子情报的特征和基础、模拟和数字系统的信噪比考虑、信号功率、极化、波数分析、天线扫描分析、脉内分析、脉冲重复间隔分析、载频分析、脉冲串去交错、确定elint参数的极限以及elint数据文件
-This is an electronic intelligence on the radar signal analysis of the electronic version, the main contents include the characteristics of electronic intelligence and infrastructure, both analog and digital system signal to noise ratio considerations, signal power, polarization, wave-number analysis, antenna scanning analysis, pulse analysis , pulse repetition interval analysis, analysis of carrier frequency, pulse staggered string to determine the limits of the parameters, as well as ELINT ELINT Data Files Platform: |
Size: 5269504 |
Author:zhang |
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Description: ASK（二进制幅度键控）是一种最简单的数字信号的载波传输，本文通过对数字信号的2ASK调制，解调在不同信噪比的情况下误码率分析，得出不同信噪比下的误码率。
通过对2ASK的仿真更好的理解了数字调制系统的组成以及各模块的功能。
-ASK (binary amplitude shift keying) is a simple digital signal carrier transmission, this paper 2ASK digital signal modulation, demodulation signal to noise ratio in different circumstances BER analysis, have come to different SNR BER. Simulation 2ASK through a better understanding of the digital modulation system, as well as the function of each module. Platform: |
Size: 52224 |
Author:徐丽丽 |
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Description: 摘 要:根据HFC网络上行信道的特性,建立了信道模型 分析了上行信道中存在的各种噪声对QPSK
调制技术的影响。结果表明在C /N (传输信道载噪比)较低的情况下,采用QPSK调制方式,可以提高系
统的抗干扰能力。
关键词: QPSK 光纤同轴电缆混合网 上行信道 噪声-Abstract: HFC network in accordance with the characteristics of the uplink channel, the establishment of a channel model an analysis of the various uplink channel noise on the impact of QPSK modulation. The results show that the C/N (transmission channel carrier-to-noise ratio) lower, the use of QPSK modulation, can improve the system of anti-interference ability. Keywords: QPSK hybrid fiber coaxial cable network uplink channel noise Platform: |
Size: 581632 |
Author:xiu |
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Description: 预先设定载频、采样率、码速率、信息代码个数和信噪比等参数，进行FSK信号的调制解调。-Pre-set carrier frequency, sampling rate, bit rate, information, code number and signal to noise ratio and other parameters for FSK signal modulation and demodulation. Platform: |
Size: 1024 |
Author:马汪 |
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Description: 利用频谱仪的gpib口测试CATV接收模块载噪比的自动测试软件-I use Spectrum Analyzer gpib test CATV receiver module carrier to noise ratio of the automatic test software Platform: |
Size: 96256 |
Author:vincent |
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Description: 实现FSK调制，由计算机随机产生二进制码元，可自主更改载频频率同时可以加入不同信噪比的白噪声。-Achieve FSK modulation, the binary code randomly generated by a computer element, change the carrier frequency can be independently the same time can be added to the white noise of different signal to noise ratio. Platform: |
Size: 1024 |
Author:方便 |
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Description: RKX-750-6B是一款经济型的超低单向接收机，适用于光纤进楼及农村中偏远的住房使用。采用国际先进的GaAs HBT集成电路技术，使光接收机具有非常低的噪音功率。在相同接收光功率的条件下，CNR要比普通的光接收机提高至少5.0dB以上，在接收光功率达-6dB时，系统的载噪比CNR仍然维持在50dB以上，从而节省发送光功率。特别是在接收机光功率较低的情况下，效果更为显著。
使用超低光功率接收机的技术，可以用比较小的投资延伸光纤传输长度，也为构造大型的光纤网络寻找了一种新的方法。一方面节省了发送光功率，节省了投资，另一方面维护了原有的网络基础。
-RKX-750-6B is an economical, ultra-low one-way receiver suitable for optical fiber into the floor, and in remote rural housing use. Adopt international advanced GaAs HBT integrated circuit technology, optical receiver has a very low noise power. The same conditions of the received optical power, CNR than the ordinary optical receiver to improve least 5.0dB or more, in the received optical power is up to-6dB, the system' s carrier to noise ratio CNR is still maintained at least 50dB, thus saving the power of the transmitted light. Especially in the case of a low optical power of the receiver, the effect is more significant. Using the ultra low optical power receiver technology that can extend the length of the optical fiber transmission with a relatively small investment, but also in order to construct a large optical fiber network to find a new method. Save on sending optical power saving investments, on the other hand the maintenance of the existing network infrastructure. Platform: |
Size: 51200 |
Author:xu chao |
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Description: Space time block coding (STBC) and beamforming
techniques are two emerging technologies that can be
employed at base station with multiple antenna to provide
transmit diversity and beamforming gain to increase signal-to-
noise ratio (SNR) of the downlink. STBC utilizes a diversity
antenna system where the antenna spacing is usually required
to be large enough, say 10 times wavelength of the carrier for
a uniform linear array (ULA) in small angular spread
environments, to obtain low-correlation/independent fading
channels. While the beamforming antenna needs to achieve
spatial directivity and the signals received at and/or
transmitted from all antennas must be correlated or coherent.
So the antenna spacing should usually be very small, e.g. half
wavelength for ULA.
Platform: |
Size: 3018752 |
Author:rashi |
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Description: GNSS接收机通道信息显示控件，用于.NetFramework窗体程序开发，可显示通道捕获、跟踪状态、环路锁定情况、载噪比、卫星号等信息。-GNSS receiver channel information display controls,.NetFramework form for program development, can display the channel capture, tracking state, loop lock, carrier to noise ratio, satellite number and other information. Platform: |
Size: 79872 |
Author:btop |
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Description: 运用噪声通道的方法对信号进行载噪比的估计-Use method of estimating noise channel carrier to noise ratio of the signal Platform: |
Size: 778240 |
Author:小怪兽 |
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Description: 基于信号包络的载噪比估计算法，对信号载噪比进行估计-Based on the signal envelope CNR estimation algorithm to estimate the signal carrier to noise ratio Platform: |
Size: 2333696 |
Author:小怪兽 |
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Description: This article contains analyses of the performance of various carrier synchronization
loops for offset quadrature phase-shift-keying (OQPSK) modulation, all
motivated in one form or another by the maximum a posteriori (MAP) estimation
of carrier phase. When they are implemented as either high or low signal-to-noise
ratio (SNR) approximations to the generic implementation suggested by the MAP
estimation of carrier phase for an OQPSK signal, it is shown that the loops behave
more like biphase than quadriphase loops in that they only exhibit a 180-deg phase
ambiguity rather than the 90-deg phase ambiguity typical of the latter. Platform: |
Size: 450560 |
Author:Alexandr |
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Description: This paper proposes and analyses an efficient wireless telecommunication system with multiple antennas to the emission and reception MIMO (multiple input multiple output) with space diversity in an OFDM (Orthogonal Frequency Di vision Multiplex). The proposed system consists to add modified Alamouti encoder to the system OFDM to improve the performance of the destination by intimately collaborating with the antennas system. We analyse the performance of a DTT (Digital Terrestrial Television) broadcasting system that includes MIMO encoder, associate with OFDM techniques, which can improve the appreciation of the quality of transmission bit error rate (BER) in terms of (C/N) carrier-to-noise ratio. Different propagation channel models and configurations are considered for each diversity scheme. This study has been carried out in the context of MIMO -OFDM improvement for the next generation of Digital Terrestrial Television broadcasting systems. Platform: |
Size: 835584 |
Author:Moyad |
Hits:
Search - carrier to noise ratio